From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 45167C001DF for ; Mon, 31 Jul 2023 14:26:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=B8kc72/PbxRHNBUihnBKsuffD34wFIUW06T/xiMdqXQ=; b=VuduOCIsvNtpXtroTa6n1vJ+st zR6mLj0BM1kcbPbWU1aV18UqeaGcdiWbNGf3h5+XcV5jVeDHzOT6v6wPqfO/AWcktsfDfr5wF5xRJ 9cA0YkdEjpZlHjT9TF9LFtjFYsLbOfcSrBXKxcT5MgoehMJBqLCKaLOybhSvnKrym5r6lzMcaPCnW ht4G+40GVf/3NPZ8GwDuWasXiqQIiGCt5pFTgnrg0zIj9SxTUXaWkQ3ZNKWD9EVMFfzizA5cGlIU+ 8MffQnOaYZZwYUGrKQ2hdmHiWUW2KQzLAJfPMC+Wm+RZDYz9aNWZRIaJv8DcbPh+wbnhiYsnalL7B 2AWrC5iw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qQTqs-00G7Q0-0F; Mon, 31 Jul 2023 14:26:26 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qQTqq-00G7PR-2T; Mon, 31 Jul 2023 14:26:24 +0000 Date: Mon, 31 Jul 2023 07:26:24 -0700 From: Christoph Hellwig To: Damien Le Moal Cc: Christoph Hellwig , Shin'ichiro Kawasaki , linux-nvme@lists.infradead.org, Keith Busch , Johannes Thumshirn Subject: Re: [PATCH] nvme: zns: limit max_zone_append by max_segments Message-ID: References: <20230731114632.1429799-1-shinichiro.kawasaki@wdc.com> <3a827ef4-4143-a7d4-f3b1-6b50837f6fd9@kernel.org> <8da417c3-f505-ebfc-c92a-509fee68cfa3@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8da417c3-f505-ebfc-c92a-509fee68cfa3@kernel.org> X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Jul 31, 2023 at 11:12:43PM +0900, Damien Le Moal wrote: > max zone append sectors limit indicates the maximum size of a zone append BIO > that can be built without ever needing splitting. > > So if we fix the zns limit, zonefs does not really need a fix, eventhough the > code would be a little weird as-is. You still need to fix splitting due to I/O layout and not just size. E.g. if your do a writev() with two non-page aligned buffers (you'll probably need a arm64 or power box to trigger it), you need to split the bio even if it trivially fits into the size limit. Similar for things like max_segment_size.